Supercharged internal-combustion engine



July 18,1944. F. M. OWNER ,3

f SUPERGHARGED INTERNAL COMBUSTION ENGINE- Filed Jan. 18, 1943 4 Shets-Sheet 1 fnwrii Owner July 18, 1944. QWNER v 2,354,047

SUPERCHARGED INTERNAL COMBUSTION ENGINE Filed Jan. 18, 1943 4 Sheets-Sheet 2 July 18, 1944. F. M.'OWNER SUPERCHARGED INTERNAL COMBUSTION ENGINE 4 Sheets-Sheet 5 Filed Jan. 18, 1945 fnvenf Frank 1% Owmr July 18, 1944. F. OWNER 2,354,047

SUPERCHARGED INTERNAL COMBUSTION ENGINE Filed Jan. 18, 1. 945 4 Sheets-Sheet! 7 Ta IMPELLEE EYE 0F rmsr s 7746: same-2 v frwenzzr Frm J: Owner first supercharger.

Patented Jul 18, 1944 Frank Morgan Owner, Bristol, England, assignor to The Bristol Aeroplane Company Limited, Bristol, England, a company of Great Britain Application January 18, 1943, Serial No. 472,767

' In Great Britain December 2, 1941 '5 Claims.

rality of gear-trains of different gear-ratios and the second supercharger is driven through a constant-ratio gear-train. Internal-combustion engines of the kind wit which the present invention is concerned are open to the objection that when the desired pressure of supercharge can be obtained by operating only the second supercharger, either the gas (which may be either air or the combustible mixture) to be supercharged is drawn through the first supercharger with consequent loss in emciency, or ducts having valves to by-pass the first supercharger and lead the medium direct to the second supercharger are provided with consequent increase in weight.

According to another feature of the present invention when the second supercharger alone is capable of producing the desired pressure of supercharge, the first supercharger is driven at such a speed as to make up the pressure-loss to which the gas is subjected in its passage through said This invention also comprises the improved construction of three-speed epicyclic gear hereinafter described, and the arrangementwhereby the low-speed gear automatically becomes operative when both higher speeds are inoperative.

In the accompanying drawings:

1 Figure 1 is a half view in central section of an arrangement of two superchargers according to the present invention, with a three-speed gear for driving one of them,

the'second supercharger.

Referring first to Figure 1, the two superchargers are mounted co-axially with the crankshaft of an engine whereof a part of the crankcase is indicated at It, and the axis of the crankshaft at II. A supercharger comprising a rotor i2 discharges by a voiute chamber l3 to the engine cylinders, and this is the second supercharger aforesaid, which is always in operation being driven from the crankshaft through a constant-ratio gear-train. The other or first supercharger is constituted by a rotor l4 discharging into a voiute chamber [5 which communicates by suitable passages, not shown, with the inlet to the rotor II. This first supercharger I4 is driven through one or other of a plurality of gear-trains of diiferent gear-ratio according to the-flight-requirements.

The engine crankshaft It has driving engagement with a co-axial extension shaft II which extends through the rotor l2 of the second supercharger and terminates at a bearing 48 between the two superchargers. The shaft is of the second supercharger is of tubular form surrounding the shaft I! and supported in bearings 20, 2| carried by the general casingof the two superchargers.

The "rotor It of the first supercharger is carried on a shaft 22 co-axial with the shaft I! which is supported by a bearing 23 thereon at one end, and is also carried by a bearing 24 on the general casing of the superchargers.

On the shaft ll near its bearing is there is mounted a driving gear 25 which carries a gear 26 meshing with'a gear 28 on a layshaft 30 and there are two or more of these layshafts disposed symmetrically around the axis II. The driving gear 25 preferably has a resilient driving coupling 3| with the shaft ll, such for example, as is described in the specification of British Patent No,

' 293,713, in order to avoid overloading the gearing from the inertia effects when accelerating or decelerating the rotors, this coupling being indicated at 3|.

The shaft 30 carries a large gear 32 which meshes with and drives a gear 31 on the shaft is carrying the rotor l2 of the second supercharger, so that the drive from the crankshaft is continuously transmitted to this supercharger, the gearratios 26, 28 and 32, 33 being so selected as to give the desired high speed to the rotor.

Each layshaft 30 also transmits a drive through a a three-speed epicyclic gear mounted in a casing 34 by a gear 35 thereon to a pinion 35-on the shaft 22 of the rotor l4. Preferably the pinion 36 is not. directly mounted on the shaft 22, but engages it through a centrifugal clutch device 31 as described in the British Patent No. 293,713 above mentioned or in U. S. Patent No. 1,729,509,

so that when the gear-ratio of the transmission is altered, the drive is taken up gradually without shock.

The construction of the three-speed gear and its controlling means is illustrated to a larger scale in Figure 3,.which shows the driving gear 26 engaging the gear 25 fast on the shaft 35. On the shaft 35, at the right-hand side in Figure 3, a radial flange or spider 35 carries a suitable numberof planet-axles 39 each of which car-. ries on a suitable bearing a double planet-wheel 45, 4|, these two wheels being of different sizes; the larger wheel 4| meshes with an internal gear 42 carried by the casing 34 which is rotatable on bearings 43, 44 and as mentioned above, carries a gear 35 which transmits the drive by the gear 35 to the first supercharger.

The planet-wheels 4| all mesh with a sunwheel 45 mounted on a shaft 45 rotatable on the shaft 35, and similarly the planet-wheels 45, mesh with a sun-wheel 41 on ashaft 45.

The control of the epicyclic transmission gear is effected by a clutch mechanism mounted in a casing 49 which is secured to the supercharger casing as at 50; the casing 49 comprises two end walls 5|, 52 respectively and there is also provided an inwardly-directed wall 53 which is also secured to the clutch-casing. Between the walls 5| and 53 there is mounted a, diaphragm 54 which is movable axially in the casing to grip clutchplates 55 between it and the wall 53, to hold them stationary; the diaphragm 54 is provided with recesses engaged by pins 55 to hold it against rotation, and it is also provided with oil-seals 51 so that it can be operated by .the admission of oil under a suitably high ressure to the space between it and the end wall 5| of the casing. The clutch-plates-55 are mounted on the shaft 48 which carries the sun-wheel 41 so that the latter can beheld stationary or released at will.

A second diaphragm 55 is arranged similarly to control a clutch-plate 55 keyed on the shaft 45 and thereby provide a similar control for the sun-wheel 45. The usual form of spring washers may be provided between the wall 53 and each of the diaphragm to maintain the clutch surfaces free from one another when the oil pressure is released.

The sun-wheels 45 and 41 are used in cooperation with their respective planet-gears to provide the medium and high speed ratios of transmission, and the low ratio transmission is provided by the following construction. The planet-carrier 35, 35 carries an extension-piece 55 in the form of an annular rim having on its inner face helical splines 5| which are engaged by corresponding splines on the outer periphery of a ring 52. On its inner face this ring is formed with a series of inwardly-directed helical teeth 53 which are adapted to engage with a similar set of teeth 54 formed on a flange 55 onand 6.

, The control and operation ofthis gear will now. be described, such control being effected by means of a clutch-control-valve of any suitable form which controls the admission and release of high pressure oil to the two diaphragms 54. 55 above mentioned. Assuming that the clutch-control-valve is set to select the medium speed drive, 011 is delivered under pressure to the left-hand side of the diaphragm 55, moving it to the right to engage and hold the clutchplate and thereby hold the sun-wheel stationary; simultaneously, the chamber to the right of the diaphragm 54 is open to drain so that the diaphragm moves to the right and releases the clutch-plates 55 and thereby leaves the sunwheel 41 free to rotate. The drive from the shaft 35 to the planet-carrier 35 and planetwheel 4| causes it to roll upon the stationary sun-wheel 45 and impart a drive to the clutchcasing 34 and thence by the gears 35, 55 to the rotor H. The sun-wheel 41 rotates idly.

If now it be desired to engage the high-speed gear, the control-valve is adjusted to admit highpressure oil to the right-hand side of the diaphragm 54, and thereby lock the clutch-plates 55 and the sun-wheel 41. Simultaneously, the space to the left of the diaphragm 55 is open to drain, thereby releasing the clutch-plate 55 and the sun-wheel 45. The drive from the shaft 35. through the planet-carrier to the planet-wheels 45 causes them to roll on the stationary sunwheel 41, and their motion is transmitted to the planets 4| which drive the casing 34 at a. high speed, and through the gears 35,35 drive the rotor H at the desired high speed.

The lowest transmission ratio is effected releasing both of the sun-wheels 45, 41, by opening the chambers for the two diaphragms 54, 55 both to drain, so that both sets of clutch-plates are released and reference may now be made to the diagrams, Figures 4, 5 and 6. The planetcarrier 35, lanets 45 and 4|, sun-wheels 45 and 41 and gear 42 on the casing are all indicated diagrammatically, and Figure 4 shows the motions of the various parts by the arrows indicated thereon. Figure 4 shows the state of affairs this rotation.

-fore rotating anti-clockwise, so that the fingers 55 click idly over the teeth 53.

In Figure 5 the state of affairs is shown when the ah-speed ratio is engaged; the planet-carrier is rotating anti-clockwise, the sun-wheel 41 (and with it the flange 55 and fingers 55) are held against rotation, the sun-wheel 45 rotates vidly and the planet 45 rolls on the stationary sun-wheel 41, thereby imparting a drive through the planet 4| to the gear 42. In this gear setting also the teeth 53 click idly over the finzers 55 owing to their relative rotations.

Figure 5 shows the arrangement when the; lowest gear ratio is used, and both of the sunwheels 45, 41 are left free to rotateidly. Since the two sun-wheels are stationary, no drive is imparted to the rotor l4 of the first super-' charg'en'and it therefore slows down, and if it stopped, so that the gear 43 were also stopped. it is clear that the planet 4| would roll on the 'gear 43 and thereby cause the planet 45 to drive the sun-wheel 41 in an anti-clockwise direction as indicated by the arrows. There is not, however,

sufficient loading on the supercharger at low speeds to cause it to stop, but the speed is reduced sufiiciently to cause the planet-:wheels to drive the sun-wheels in an anti-clockwise direction, and therefore engage the fingers 66 with the teeth 63 and thereby tend to drive the ring 62 at a higher speed thanthat of the planetcarrier. Its splined engagement 61 with the planet-carrier causes it to be moved to the right (see Figure 3), so as to mesh the teeth 63 with the teeth 64 so that the sun-wheel 41 islocked to the planet-carrier and the whole gear rotates solid, giving the desired low-speed transmission to the supercharger rotor 14 suflicient to compensate for the pressure loss of the air or gas passing through it.

When the medium speed ratio is engaged, by locking the sun-wheel 45, the first engagement of the clutch members loads the planet-wheel 4|, and thereby loads the interengaging helical teeth 63, 64, so that they automatically disengage, and as soon as they are disengaged, the helical splines 6| complete the lateral movement of the ring 62 into the free position shown in Figure 3. As scenes the teeth 63, 64 are disengaged, the. rotation of the sun-wheel 41 is reversed, as indicated in Figure 4, so that the .fingers 66 click over the teeth 63 as previously described. 1

It will thus be appreciated that the control of the clutches for the sun-wheels 45, 4'! provides alternative drives at three diflerent speeds for the rotor M of the first supercharger.

.Figure 2 illustrates a'modifled construction of the present invention in which a two-speed gear is provided for the drive of the rotor l4 oi the first supercharger, and for this purpose, a twospeed transmission assemblage described in the specification of British Letters Patent No. 465,612 is substituted for the three-speed gear.

The construction illustrated in Figure 2 is conveniently identical with that of Figure 1 in so far as the constant ratio drive to the second supercharger rotor I2 is concerned, and the only difference is that the three-speed 'gear in the casing 34 replaced by a two-speed gear indicated generally by the reference ID; the drive as far as the gear 25 is similar to that illustrated in Figure 1, but the gear 25 carries two gears 26, 21 which mesh respectively with gears 28, 29. The gears 26, 21 are used in the same way as in Figure 1, butthe gear 29 is additional, being used for the two-speed gear 10.- In order to make the two constructions interchangeable, the double gears 26, 21 may be used in Figure 1, and are so illustrated, although the gear 21 is idle in that case.

Iclaim:

1. In combination, a supercharger, multispeed transmission for driving said supercharger comprising low and higher speed gear ratio units, means to selectively shift the higher speed ratio units into and out of connection with 7 said supercharger, and automatic means for causing low gear ratio connection to thesupercharger at such timesas the supercharger runs free of the higher speed ratios, said automatic. means comprising two relatively rotary and axially shifta'ble parts, means to cause relative axial parts in opposite directions, and means carrying one of said members for locking the transmission to rotate as a whole and provide said low gear ratio drive. 7

2. In combination, a supercharger, multispeed transmission for driving said supercharger comprising a plurality of higher speed ratio units, a low speed unit comprising tworelatively rotatable and relatively axially movable parts, means between said parts for causing one of the parts to slide axially when the parts are relatively rotated, intermeshing members normally out of mesh and moved into and out of mesh by the axial sliding of said part, means connecting one of said members with the other units of the transmission to cause the transmission to be interlocked and to rotate as a whole when said members are intermeshed, and ratchet means carried by said lastnamed means for en-, gaging the other of said intermeshing parts.

3. In combination, a. supercharger, multispeed transmission for. driving said supercharger comprising a continuously driven carrier, medium and high speed planet gears rotatably supported on said carrier, sunwheels independently mounted in connection with said planet gears, a ring gear in driving relation to said supercharger and in driven relation to said planet gears, means for selectively arresting the motion of either of said sunwheels to cause said ring gear to rotate at a. selected medium or high speed, a low speed gear unit comprising means to free said low gear ratio unit when e ither of said medium or high speed ratios are engaged and to further automatically connect said low gear ratio to said ring gear whenever the medium and high speed ratios are disengaged.

4. In the combination of claim 3, said low gear unit comprising an annular rim ailixed to said carrier and rotated therewith, a ring within said rim rotatable and axially slidable independently of said rim, helical splines between said rim and ring, a shaft connected to one of said sunwheels, normally disengaged helical teeth on said shaft and ring, and a series of fingers pivoted on said shaft and engaging the teeth of said ring.

. ing said first-stage supercharger comprising me- 5. In combination first and second-stage superchargers connected together in series 1n,'Wh1ch the gas first passes through the'first-stage super charger and then is delivered to, and passes through, said second supercharger, engine driven means for driving said second-stage superchargerat substantially constant speed and-at a minimum at which the second supercharger alone is capable of producing the desired-pros sure or supercharge at minimum requirements of the engine, a multi-speed transmission for driv- 5 stage supercharger with said low gear ratio unit shifting of the parts when rotated relatively to one another, intermeshing members caused to enmesh and disengage on axial movement ofthe whenever the higher speed ratio unitsare disengaged whereby at all times to cause the firststage supercharger to be driven at such a minimum speed as" to makeup the pressure loss to which the gas is subjected in its pe through said first s p rcharger. a

* FRANK MORGAN OWNER. 

